Assessment of tongue posture in class I malocclusion with vertical malrelations

Abstract

Introduction Tongue is a soft muscular tissue which is mainly made of mucosa, muscles, vascular and nerve supply. The mucosa of body is formed from the first pharyngeal arch and third pharyngeal arches; while the skeletal muscles develop from myoblast that migrate from occipital somite's. Aim Owing to its effect on the building structures all around and vital functions, this study was carried out to assess the tongue posture in vertical malrelations; in class I malocclusion. Materials and methods A cephalometric study was carried out on 153 adult patients (76 female, 75 male) from 17 to 22 years old) with skeletal class I. The sample was selected according to the mandibular plane angle (SN/GO-GN) and categorized according to vertical facial pattern into; high angle (SN/MP >37), low angle (SN/MP <27) and average angle (SN/MP 32 ± 5°); including 26 females and 25 males in each group. The tongue position was calculated along horizontal line passing through the incisal edge of the lower central incisor to the cervical distal third of the lower second molar and extending posteriorly. Taking the cervical area as a center, six angles will be drawn at 0°, 30°, 60°, 90°, 12°, and 150°. The contours of the dorsum of the tongue and the palate and six distances will be measured at 0°, 30°, 60°, 90°, 120°, and 150° between tongue and palate contour. Results Tongue positions were found to be higher in position in skeletal class I malocclusion in low and high mandibular plane (posterior part of the tongue); on the other, lower tongue position (anterior part) was found in increased mandibular plane angle without sex differences Conclusion Tongue position is affected by the position of the mandible in vertical plane; regarding the anterior or posterior part without sex differences.